Load Balancing and Failover

Load balancing and failover functions depend on the individual components in the cluster. For example, load balancing is not applicable to Service Engines (SE), and is protocol specific for some of the Binding Components (BC). For example, the HTTP Load Balancer is required for SOAP transactions, while the File BC, JMS BC, and FTP BC all have built-in load balancing.

GlassFish provides additional support for high availability, load balancing, and failover with the HTTP Load Balancer plug-in. The HTTP Load Balancer distributes incoming HTTP and HTTPS transactions among the instances in a cluster and also fails over requests to another server instance if the original server instance becomes unavailable. The HTTP BC does not have its own load balancing capabilities, making the HTTP Load Balancer plug-in a useful tool when implementing the HTTP BC in a clustered environment. For more information, see Chapter 5, Configuring HTTP Load Balancing, in Sun GlassFish Enterprise Server 2.1 High Availability Administration Guide.

Load balancing and failover for the JMS BC is provided through a JMS broker cluster. For more information, see Chapter 10, Java Message Service Load Balancing and Failover, in Sun GlassFish Enterprise Server 2.1 High Availability Administration Guide.